Frequently Asked Questions

Tuesday, 18 January 2011

Written by John Nutting

Frequently Asked Questions

What's the biggest market for cans in the world?

North America is the biggest market for cans, using almost 100 billion for drinks and about 30 billion for food, industrial products and aerosols. All US-made drinks cans are aluminium, representing about 20 percent of all the aluminium produced in the world. The biggest user of cans in the US is Coca-Cola whose cans are made from about 300,000 tonnes of aluminium sheet every year. About 80 percent of the food cans made in the US are from tinplate, the remainder from aluminium.

The beer and beverage markets use about 52bn cans a year, with the proportion of tinplate and aluminium cans being about 25/75 percent in 2009. Estimates for the food can business in Western Europe indicate that about 24bn cans are made, three-quarters of which are tinplate. But a considerable tonnage of steel is used for industrial applications such as pails and drums.

How many drinks cans are produced worldwide?

For all kinds of drinks, including beers, soft drinks and juices, about 280 billion (280,000,000,000) are made every year worldwide.

Who invented the food can?

A Frenchman, Nicolas Appert, is widely regarded as the first to devise the idea of preserving foods in containers by driving out the air with heat before sealing. He used glass jars to win a prize early in the 19th century awarded by Emperor Napoleon to provide preserved foods for the troops at the Russian front. Another Frenchman, Philippe de Girard, first demonstrated canned foods at the Royal Society in London in 1810 and, soon after, an Englishman Peter Durand patented some ideas for a similar process that could include the tinplate can. Durand was in effect acting as an agent for de Girard. The first cans used solder for sealing the seams. It wasn't until 1880 that mechanical seaming processes were developed. A proper hermetic double seam was developed in 1897 when Max Ams and Julius Brenzinger in the US first made the process work at high speeds and was soon after developed by the Sanitary Can Company of the US.

Who was the first canmaker?

Bryan Donkin and John Hall acquired the patent from Peter Durand for £1,000 and in 1813 started manufacturing canned foods at a factory in south London at Bermondsey, supplying the British Admiralty. The canned foods, which were expensive by the standards of the day, were used for expeditions.

How does metal compare with other packaging types?

* Cans are stronger than plastics and cartons, and provide better protection. * Cans preserve and protect the product from damage, light, oxygen, extremes of temperature and attack from contamination. * Cans are lightweight. No other packaging would be able to withstand the necessary heat processing for preserved foods with so little weight. * Less secondary packaging is required for transportation because cans are robust.

What is the sustainability record for metal packaging?

* Canned foods make better use of the raw products, reducing food waste. * Cans offer a long shelf life for food products, often up to three years. * Cans are an ambient pack, meaning that they don’t require cooling systems in the supply chain, thereby saving energy. * Cans are made from material produced with more than 50 percent recycled content. * Because of their long shelf life, canned products are less likely to be thrown away before their sell-by date, saving on landfill.

How many cans are recycled?

* Around 7.5 million tonnes of steel cans are recycled every year worldwide (2007), equivalent to a recycling rate of 68 percent according to the World Steel Association’s records for its 37 member countries. * In some countries the can recycling rate reaches 95 percent. * In Europe the recycling rate for steel cans is 69 percent* with 2.5 million tonnes recovered. * The recycling rate in Europe for aluminium drinks cans was 64 percent in 2009. In North America it was 57.4 percent for 2009.

Do cans have a low carbon footprint?

* The more packaging is recycled the lower the carbon dioxide emissions from the manufacturing system. So with a high recycling rate cans have a low carbon footprint. * As recycling rates increase, the amount of virgin material and energy required for manufacturing cans is reduced, producing significant environmental savings such as: * 75 percent less energy is required to make steel than from virgin materials. * 95 percent less energy is required to make primary smelted aluminium. * With a steel recycling rate of 66 percent, carbon dioxide emissions are cut by 40 percent.

What happened to ring-pulls?

The original design of easy-open lid, introduced on drinks cans from about 1963, used a ring-pull design in which the tab detached from the lid completely. Environmental considerations in the US and Europe led to the development in 1975 of the stay-on tab which remains on the lid after opening. Almost all US and European drinks cans use stay-on tabs, and although it is being introduced elsewhere, there are many markets which prefer ring-pulls (for example the Middle East and China) because of concerns that any contamination from the tab will find its way into the drink after opening.

How are food cans made?

Food cans are still mostly made from tinplate using a three-piece construction in which the body is rolled from sheet into a cylinder, welded along the side seam and then has a lid seamed onto one end. This is delivered to the customer for filling after which the top lid is seamed on. Three-piece cans and ends have a variety of lacquers and enamels applied before manufacturing which protect the contents and ensure a long shelf life. Manufacturing speeds depend on the size of the can, and range from 50 per minute for large pails to more than 1,000 per minute for small fish and fruit cans. Some food cans are made using the same process as drinks cans, being drawn in presses from sheet. This process is more popular in North America where a number of redundant drinks can lines were converted for this application. Most fish cans are made using drawing techniques.

How are easy-open lids made?

Easy-open lids were first introduced in the 1960s for drinks cans and are now almost universally employed. Food can easy-open ends, which are called full-aperture because the most of the lid is removed on opening, have become more popular since the mid-1990s and are used on two-thirds of all food cans in Europe, less so in the US. Lids are made from lacquered sheet (tinplate, tin-free steel or aluminium) in a press and then curled to form the hook for the seam. Easy open ends are scored to about a third of the sheet thickness in a conversion press which also forms and applies the pull tab. Key to the success of the process is the formation of a rivet which enables the tab to be attached without piercing or welding the lid, thereby not affecting the protective coating.

How are drink cans manufactured?

So-called two-piece drinks cans, which are the most widely used containers worldwide, are made from aluminium alloy sheet measuring about 0.25mm thick (or less frequently from tinplate sheet of about 0.20mm) which is formed in presses into cups and then into cans using a wall-ironing process which reduces the wall thickness to less than 0.1mm (100 microns). The cans are then coated with protective lacquers and printed with the labels before the neck and flange is formed so that the lid can be securely seamed on after it is filled at a drinks plant. Cans are made at up to 5,000 per minute in the most productive plants. Typical aluminium can weight is now about 12 grams, less than half of what they were when they were first made in the early 1960s. Two-piece cans made from tinplate, which was first introduced into Europe in the early 1970s, weigh about 20 grams. Further lightweighting of cans continues, because the metal in a can represents about 65-70 percent of the finished cost. After cigarette manufacturing, canmaking is the fastest unit-per-minute process.

Is there growth in the metal packaging markets?

Most certainly. In Europe, demand for beverage cans grew by ten percent a year between 2006 and 2008, much of which has come from Eastern Europe and Russia, but those markets have since declined. South American demand continues to rise with almost 12 percent growth a year in Brazil. China and some parts of south east Asia are also growing at almost 10 percent. Beverage can demand growth in 2010 was about 4 percent a year. Within the metal packaging sectors, metal bottles with resealable caps are regarded as having the most potential.